<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<input type="button" value="点击我" id="btn1" />
	</body>
	<script>
		(function(){
			var btn1 = document.getElementById('btn1');
			btn1.addEventListener('click',function(){
				alert("a");
			});
			//装饰者模式
			
		})();
	</script>
</html>
